This is a repack of the Cave Story (Doukutsu) from RetroArch (Vita) v1.3.6, Other platforms of RetroArch the game comes included the files can be found in the libretro git (here) however I slimmed the files down in the included download with vpk. Simply follow the installation Instructions in the Installation tab.

Also, a tip as this libretro only plays this single game, you can make selecting the game each time a bit easier . View "Suggested Config" tab for more details on this tip​